code: def test_no_split(random_xy_dataset_regr):
      X, y = random_xy_dataset_regr
      # With only one split, the method should raise a ValueError
      cluster_method = DummyCluster(n_splits=1)
      kf = KlusterFoldValidation(cluster_method=cluster_method)
      with pytest.raises(ValueError):
          for train_index, test_index in kf.split(X):
              assert len(train_index) > 0
              assert len(test_index) > 0
  
file_path: scikit-lego/tests/test_model_selection/test_klusterfold.py
imports: import numpy
  import pytest
  from sklearn import clone
  from sklearn.base import BaseEstimator
  from sklearn.cluster import KMeans, MiniBatchKMeans
  from sklearn.pipeline import make_pipeline
  from sklearn.preprocessing import StandardScaler
  from sklego.model_selection import KlusterFoldValidation
  from tests.conftest import id_func
label_desc: Use image node_id 3 for calling a global function with example usage: test_no_split(random_xy_dataset_regr) without return types